Asymmetric Total Synthesis of Caribenol A via an Intramolecular Diels–Alder Reaction
作者:Jing-Chun Han、Lian-Zhu Liu、Yuan-Yuan Chang、Guo-Zong Yue、Jie Guo、Li-Yan Zhou、Chuang-Chuang Li、Zhen Yang
DOI:10.1021/jo4006156
日期:2013.6.7
natural product with an intriguing tetracyclic framework, has been achieved. The synthesis features an intramolecularDiels–Alder (IMDA) reaction for the facile construction of the tricyclic [5–7–6] skeleton of caribenol A (1) and a biomimetic oxidation reaction for the formation of the 2-hydroxyfuran-2(5H)-one motif of caribenol A (1) as key steps. This synthetic approach also reveals that the sp2 carbon
Enantio-and diastereoselective synthesis of 4-alpha-alkylcarbovir derivatives 5 were achieved based on Sakai's asymmetric alkylation of beta-keto esters. The key carbocyclic intermediate 14 was synthesized from 8 via an eleven-step sequence. Coupling of 14 with 2-amino-6-chloropurine followed by desilylation and subsequent hydrolysis gave the target compounds 5 in moderate yields. (C) 1998 Elsevier Science Ltd. All rights reserved.